1. Field
Aspects of embodiments of the present invention relate to a flat panel display and a data driver of a flat panel display and a driving method thereof.
2. Description of the Related Art
In recent years, various flat panel displays that can overcome disadvantages of cathode ray tubes, e.g., the heavy weights and large volumes of the cathode ray tubes, have been developed. Such flat panel displays include liquid crystal displays (LCDs), field emission displays (FEDs), plasma display panels (PDPs), and organic light emitting displays (OLEDs).
Flat panel displays can be classified into active matrix type displays and passive matrix type displays. An active matrix type display includes a plurality of scan lines and a plurality of data lines, and a plurality of pixels connected to the lines and arranged in a matrix. Each pixel includes a thin film transistor as a switching device controlled by scan signals applied to a corresponding scan line.
That is, an active matrix type flat panel display includes pixels arranged in a matrix, a data driver (or data drive circuit) for driving data lines connected to the pixels, and a scan driver (or data drive circuit) for driving scan lines connected to the pixels.
Here, the scan driver sequentially supplies scan signals during horizontal periods to perform an operation of selecting pixels to which data signals are supplied, and the data driver supplies data signals corresponding to input data to the selected pixels to which the scan signals are applied to display an image using the pixels.
The data driver includes a plurality of amplifiers at an output terminal to output data signals to the data lines. However, there exist random DC offsets in the amplifiers for channels, so there exist variations between data signals that are actually output by the amplifiers even if data signals corresponding to the same value are supplied to the amplifiers.
The output variations between the channels that occur in the data driver including the plurality of amplifiers appear as brightness differences between vertical lines, and cause a deterioration in image quality in which stripes appear in the screen (or image).
In particular, of the active matrix type flat panel displays, organic light emitting displays undergo screen deteriorations due to the output variations between channels (or columns) more severely than liquid crystal displays employing reversal drive schemes.